binman: Split control.WriteEntryToImage() into separate functions

This code has three distinct phases:

1. The image is loaded and the state module is set up
2. The entry is written to the image
3. The image is repacked and written back to the file

Split the code out with three separate functions, one for each phase.
Signed-off-by: NSimon Glass <sjg@chromium.org>

tools/binman/control.py

@@ -169,6 +169,62 @@ def ExtractEntries(image_fname, output_fname, outdir, entry_paths,
     return einfos
 
 
+def BeforeReplace(image, allow_resize):
+    """Handle getting an image ready for replacing entries in it
+
+    Args:
+        image: Image to prepare
+    """
+    state.PrepareFromLoadedData(image)
+    image.LoadData()
+
+    # If repacking, drop the old offset/size values except for the original
+    # ones, so we are only left with the constraints.
+    if allow_resize:
+        image.ResetForPack()
+
+
+def ReplaceOneEntry(image, entry, data, do_compress, allow_resize):
+    """Handle replacing a single entry an an image
+
+    Args:
+        image: Image to update
+        entry: Entry to write
+        data: Data to replace with
+        do_compress: True to compress the data if needed, False if data is
+            already compressed so should be used as is
+        allow_resize: True to allow entries to change size (this does a re-pack
+            of the entries), False to raise an exception
+    """
+    if not entry.WriteData(data, do_compress):
+        if not image.allow_repack:
+            entry.Raise('Entry data size does not match, but allow-repack is not present for this image')
+        if not allow_resize:
+            entry.Raise('Entry data size does not match, but resize is disabled')
+
+
+def AfterReplace(image, allow_resize, write_map):
+    """Handle write out an image after replacing entries in it
+
+    Args:
+        image: Image to write
+        allow_resize: True to allow entries to change size (this does a re-pack
+            of the entries), False to raise an exception
+        write_map: True to write a map file
+    """
+    tout.Info('Processing image')
+    ProcessImage(image, update_fdt=True, write_map=write_map,
+                 get_contents=False, allow_resize=allow_resize)
+
+
+def WriteEntryToImage(image, entry, data, do_compress=True, allow_resize=True,
+                      write_map=False):
+    BeforeReplace(image, allow_resize)
+    tout.Info('Writing data to %s' % entry.GetPath())
+    ReplaceOneEntry(image, entry, data, do_compress, allow_resize)
+    AfterReplace(image, allow_resize=allow_resize, write_map=write_map)
+
+
 def WriteEntry(image_fname, entry_path, data, do_compress=True,
                allow_resize=True, write_map=False):
     """Replace an entry in an image
@@ -189,26 +245,12 @@ def WriteEntry(image_fname, entry_path, data, do_compress=True,
     Returns:
         Image object that was updated
     """
-    tout.Info("WriteEntry '%s', file '%s'" % (entry_path, image_fname))
+    tout.Info("Write entry '%s', file '%s'" % (entry_path, image_fname))
     image = Image.FromFile(image_fname)
     entry = image.FindEntryPath(entry_path)
-    state.PrepareFromLoadedData(image)
-    image.LoadData()
+    WriteEntryToImage(image, entry, data, do_compress=do_compress,
+                      allow_resize=allow_resize, write_map=write_map)
 
-    # If repacking, drop the old offset/size values except for the original
-    # ones, so we are only left with the constraints.
-    if allow_resize:
-        image.ResetForPack()
-    tout.Info('Writing data to %s' % entry.GetPath())
-    if not entry.WriteData(data, do_compress):
-        if not image.allow_repack:
-            entry.Raise('Entry data size does not match, but allow-repack is not present for this image')
-        if not allow_resize:
-            entry.Raise('Entry data size does not match, but resize is disabled')
-    tout.Info('Processing image')
-    ProcessImage(image, update_fdt=True, write_map=False, get_contents=False,
-                 allow_resize=allow_resize)
-    tout.Info('WriteEntry done')
     return image
 
 def PrepareImagesAndDtbs(dtb_fname, select_images, update_fdt):